Abstract: This article analyzed the main issues in the wastewater treatment process of a biotechnology company's wastewater treatment plant and proposed technical modifications. Adhering to the principle of low-cost investment and making full use of existing structures and supporting equipment, the wastewater process modifications included separating and treating workshop wastewater based on its quality, replacing Fenton oxidation with chemical phosphorus removal, and changing from anaerobic ammonium oxidation to anaerobic ammonium oxidation combined with A/A/O operation. These modifications ensured the stable operation of the IC anaerobic reactor, maintained the activity of anaerobic granular sludge, enhanced the nitrogen and phosphorus removal system's resilience, achieved stable compliance with discharge standards for total nitrogen and total phosphorus, and reduced the operating costs of wastewater treatment. The cost of power and auxiliary materials per ton of wastewater decreased from 2.77 yuan/m³ to 2.54 yuan/m³.